02 GSM Fundamentals

download 02 GSM Fundamentals

of 27

Transcript of 02 GSM Fundamentals

  • 7/30/2019 02 GSM Fundamentals

    1/27

    HUAWEI TECHNOLOGIES CO., LTD. All rights reserved

    www.huawei.com

    Internal

    GSM Fundamentals

  • 7/30/2019 02 GSM Fundamentals

    2/27

    HUAWEI TECHNOLOGIES CO., LTD. Page 2All rights reserved

    Chapter 1 GSM System OverviewChapter 1 GSM System Overview

    Chapter 2 GSM Network StructureChapter 2 GSM Network Structure

    Chapter 3Chapter 3 Service Area and Number PlanningService Area and Number PlanningChapter 4Chapter 4 Channels on the Wireless InterfaceChannels on the Wireless Interface

  • 7/30/2019 02 GSM Fundamentals

    3/27

    HUAWEI TECHNOLOGIES CO., LTD. Page 3All rights reserved

    GSM system overview

    The GSM system is a frequency- and time-division cellular system,

    each physical channel is characterized by a carrier frequency and a

    time slot number

    Cellular systems are designed to operate with groups of low-power

    radios spread out over the geographical service area. Each group of

    radios serve MSs presently located near them. The area served by

    each group of radios is called a CELL

    Uplink and downlink signals for one user are assigned different

    frequencies, this kind of technique is called Frequency Division Duplex

    (FDD) Data for different users is conveyed in time intervals called slots ,

    several slots make up a frame. This kind of technique is called Time

    Division Multiple Access (TDMA)

  • 7/30/2019 02 GSM Fundamentals

    4/27

    HUAWEI TECHNOLOGIES CO., LTD. Page 4All rights reserved

    Multiple Access Technique

    Multiple Access Technique allows many subscribers to use the

    same communication medium. There are three kinds of basic Multiple Access Technique :

    FDMA , TDMA and CDMA.

    GSM system adopt FDD-TDMA (FDMA and TDMA together).

  • 7/30/2019 02 GSM Fundamentals

    5/27

    HUAWEI TECHNOLOGIES CO., LTD. Page 5All rights reserved

    FDMA

    FDMA uses different frequency

    channels to accomplish

    communication.

    The whole frequency spectrum

    available is divided into many

    individual channels (for

    transmitting and receiving)every

    channel can support the traffic for

    one subscriber or some control

    information.

    Frequency

    Time

  • 7/30/2019 02 GSM Fundamentals

    6/27

    HUAWEI TECHNOLOGIES CO., LTD. Page 6All rights reserved

    TDMA

    TDMA accomplishes the

    communication in different

    timeslot.

    A carrier is divided into

    channels based on time.

    Different signals occupy

    different timeslots in certain

    sequence , that is , many

    signals are transmitted on

    the same frequency in

    different time.Time

    Frequency

  • 7/30/2019 02 GSM Fundamentals

    7/27

    HUAWEI TECHNOLOGIES CO., LTD. Page 7All rights reserved

    GSM 900GSM 900

    Duplex Separation: 45MHz

    Channel Bandwidth: 200KHz

    The Frequency Spectrum

    Uplink

    890 915 935 960MHz

    Downlink

  • 7/30/2019 02 GSM Fundamentals

    8/27

    HUAWEI TECHNOLOGIES CO., LTD. Page 8All rights reserved

    Duplex Separation: 95MHzChannel Bandwidth: 200KHz

    Base Station Receive

    1710 1785 1805 1880MHz

    Base Station Transmit

    DCS 1800DCS 1800

    The Frequency Spectrum

  • 7/30/2019 02 GSM Fundamentals

    9/27

    HUAWEI TECHNOLOGIES CO., LTD. Page 9All rights reserved

    Chapter 1 GSM System OverviewChapter 1 GSM System Overview

    Chapter 2 GSM Network StructureChapter 2 GSM Network Structure

    Chapter 3Chapter 3 Service Area and Number PlanningService Area and Number Planning

    Chapter 4Chapter 4 Channels on the Wireless InterfaceChannels on the Wireless Interface

  • 7/30/2019 02 GSM Fundamentals

    10/27

    HUAWEI TECHNOLOGIES CO., LTD. Page 10All rights reserved

    Interface Between Different Entities

    GSM /GPRS BSS

    BTS

    BSC

    BTS

    BSC

    PCUSS7

    SMS system

    PSTN

    ISDN

    Internet,

    Intranet

    MSC/VLR GMSC

    HLR/AUC

    SGSN

    CG BG

    GGSN

    GPRS backbone

    Other PLMN

    A

    Gb

    Gi

    Gp

    Ga

    Abis

    Um

    MS

    MS

    OMC

  • 7/30/2019 02 GSM Fundamentals

    11/27

    HUAWEI TECHNOLOGIES CO., LTD. Page 11All rights reserved

    Chapter 1 GSM System OverviewChapter 1 GSM System Overview

    Chapter 2 GSM Network StructureChapter 2 GSM Network Structure

    Chapter 3Chapter 3 Service Area and Number PlanningService Area and Number Planning

    Chapter 4Chapter 4 Channels on the Wireless InterfaceChannels on the Wireless Interface

  • 7/30/2019 02 GSM Fundamentals

    12/27

    HUAWEI TECHNOLOGIES CO., LTD. Page 12All rights reserved

    Service Area

    PLMN service area

    ......

    Service Area

    MSC service area...

    Location area...

    cell

    PLMN service area PLMN service area

    MSC service area...

    Location area...

    cell

  • 7/30/2019 02 GSM Fundamentals

    13/27

    HUAWEI TECHNOLOGIES CO., LTD. Page 13All rights reserved

    LAI

    Location Area Identification

    The LAI is the international code for a location area.

    MCC: Mobile Country CodeIt consists of 3 digits .For example: The MCC of China is "460"

    MNC: Mobile Network CodeIt consists of 2 digits .

    For example: The MNC of China Mobile is "00"LAC: Location Area CodeIt is a two bytes hex code.

    The value 0000 and FFFF is invalid.For example: 460-00-0011

    MCC MNC LAC

  • 7/30/2019 02 GSM Fundamentals

    14/27

    HUAWEI TECHNOLOGIES CO., LTD. Page 14All rights reserved

    CGI

    The CGI is a unique international identification for a cell

    The format is LAI+CILAI: Location Area Identification

    CI: Cell Identity. This code uses two bytes hex code to

    identify the cells within an LAI.

    For example : 460-00-0011-0001

    CGI: Cell Global Identification

  • 7/30/2019 02 GSM Fundamentals

    15/27

    HUAWEI TECHNOLOGIES CO., LTD. Page 15All rights reserved

    BSIC

    NCC: PLMN network color code. It comprises from 0-7. Itallows various neighboring PLMNs to bedistinguished.

    BCC: BTS color code. It comprises from0-7, used todistinguish different cells assigned the samefrequency!

    NCC BCC

    BSIC

    BSICBase Station Identification Color Code)

  • 7/30/2019 02 GSM Fundamentals

    16/27

    HUAWEI TECHNOLOGIES CO., LTD. Page 16All rights reserved

    Chapter 1 GSM System OverviewChapter 1 GSM System Overview

    Chapter 2 GSM Network StructureChapter 2 GSM Network Structure

    Chapter 3Chapter 3 Service Area and Number PlanningService Area and Number Planning

    Chapter 4Chapter 4 Channels on the Wireless InterfaceChannels on the Wireless Interface

  • 7/30/2019 02 GSM Fundamentals

    17/27

    HUAWEI TECHNOLOGIES CO., LTD. Page 17All rights reserved

    2 30 16 74 52 3

    The physical channel is the medium over which theinformation is carried: 200KHz and 0.577ms

    0 1

    TDMA FRAME

    Timeslot

    The information carried in one timeslot is called a burst

    The information carried in one timeslot is called a burst

    Physical Channel and Logical Channel

    The logical channel consists of the information carriedover the physical channels

    TDMA FRAME

  • 7/30/2019 02 GSM Fundamentals

    18/27

    HUAWEI TECHNOLOGIES CO., LTD. Page 18All rights reserved

    Two types of Logical Channel

    Traffic Channel (TCH) :

    Transmits traffic information, include dataand speech.

    Control Channel (CCH) :

    Or Signaling Channel, transmits all kinds ofcontrol information.

  • 7/30/2019 02 GSM Fundamentals

    19/27

    HUAWEI TECHNOLOGIES CO., LTD. Page 19All rights reserved

    Traffic Channel (TCH)

    TCH

    Traffic Channels

    Speech

    TCH/FS

    Data

    TCH/HSTCH/9.6 TCH/2.4

    TCH/4.8

    TCH Traffic Channel

    TCH/FS Full rate Speech ChannelTCH/HS Half rate Speech ChannelTCH/9.6 Data Channel 9.6kb/sTCH/4.8 Data Channel 4.8kb/sTCH/2.4 Data Channel 2.4Kb/s

  • 7/30/2019 02 GSM Fundamentals

    20/27

    HUAWEI TECHNOLOGIES CO., LTD. Page 20All rights reserved

    FCCHSCH

    CCH (Control Channels)

    DCCH

    SDCCH

    BCH

    BCCH Synch. CH.ACCH

    SACCHFACCH CCCH

    RACH CBCH

    PCH/AGCH

    Broadcast Control Channel BCCHCommon Control Channel CCCH

    Dedicated Control Channel DCCH

    Associated Control Channel ACCH

    Control Channel (CCH)

  • 7/30/2019 02 GSM Fundamentals

    21/27

    HUAWEI TECHNOLOGIES CO., LTD. Page 21All rights reserved

    CCH

    BCH

    BCCHSynch.

    Channels

    SCH FCCH

    The information carried on the BCCH

    is monitored by the MS

    periodically when it is in idle mode

    BCCH: Broadcast Control Channel

    FCCH: Frequency Correction Channel

    SCH: Synchronization Channel

    Broadcast Control Channel BCCH

  • 7/30/2019 02 GSM Fundamentals

    22/27

    HUAWEI TECHNOLOGIES CO., LTD. Page 22All rights reserved

    CCH

    CCCH

    RACHuplink

    CBCHdownlink

    PCH/AGCHdownlink

    The CCCH is responsible for

    transferring control informationbetween all mobiles and thenetwork.

    RACH: Random Access Channel

    PCH: Paging Channel

    AGCH: Access Granted Channel

    CBCH: Cell Broadcast Channel

    Common Control Channel CCCH

  • 7/30/2019 02 GSM Fundamentals

    23/27

    HUAWEI TECHNOLOGIES CO., LTD. Page 23All rights reserved

    CCH

    DCCH

    SDCCH

    FACCH SACCH

    DCCH is assigned to a single

    wireless connection formeasurement and handoverpurpose.SDCCH: Stand-alone Dedicated

    Control ChannelACCH: Associated Control ChannelSACCH: Slow Associated

    Control ChannelFACCH: Fast Associated Control

    Channel

    ACCH

    Dedicated Control Channel DCCH

  • 7/30/2019 02 GSM Fundamentals

    24/27

    HUAWEI TECHNOLOGIES CO., LTD. Page 24All rights reserved

    RACH CCCH CCH

    SDCCH

    SACCH

    FACCH

    TCH/F

    TCH/H

    DCCH

    TCH

    DCH

    Uplink Logical channel

  • 7/30/2019 02 GSM Fundamentals

    25/27

    HUAWEI TECHNOLOGIES CO., LTD. Page 25All rights reserved

    FCCH

    SCH

    BCCH

    PCH

    AGCH

    BCCH

    CCCH

    CCH

    SDCCH

    SACCH

    FACCH

    TCH/F

    TCH/H

    DCCH

    TCH

    DCH

    Downlink Logical channel

  • 7/30/2019 02 GSM Fundamentals

    26/27

    HUAWEI TECHNOLOGIES CO., LTD. Page 26All rights reserved

    Allocate signaling channel

    FCCH

    SCHBCCH

    PCH

    RACH

    AGCH

    SDCCH

    SDCCHTCH

    FACCH

    Power-off

    Idle mode

    Dedicated mode

    Idle mode

    How to use these channels?

    Search for frequency correction burst

    Search for synchronous burst

    Extract system information

    Monitor paging message

    Send access burst

    Set up the call

    Allocate voice channel

    Conversation

    Release the call

  • 7/30/2019 02 GSM Fundamentals

    27/27

    www.huawei.com

    Thank You